extension to 60 years lifetime - sfen...plim 2012 - 14-18 may 2012 - salt lake city, usa. sfen...
TRANSCRIPT
PLIM 2012 - 14-18 May 2012 - Salt Lake City, USA.
SFEN Conference “Atoms
for the future” October
22nd-25th 2012
Extension to 60 years
lifetime
J.M.Moroni
EDF Nuclear Engineering Division
Summary
• Elements on EDF NPPs life extension program
• Asset management
• Improvement of nuclear safety
• Main challenges
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
EDF nuclear power plants fleet
58 reactors in operation
1 reactor (EPR) under construction
Technology : PWR
Spread out over 19 sites
Nuclear generation = 80 % Total
Electricity Generation
Flamanville
Paluel
Penly
Gravelines
Chooz
Cattenom
Fessenheim Nogent-sur-Seine
St-Laurent
Chinon
Civaux
Le Blayais
Golfech Tricastin
Cruas St-Alban
Bugey
Dampierre
Belleville
NPP PWR
900 MW
PWR
1300 MW
PWR N4
1450 MW
EPR
1630 MW
Nb
Unit 34 20 4
1 under
construction
License Westinghouse Areva & al.
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Figure 1
Renouvellement étalé sur 30 ans (2020-2050)
rythme de construction 2000MW/an
Génération 3+
Génération 4
Parc Actuel
durée de vie 40 ans
Prolongation au delà 40ans
0
10000
20000
30000
40000
50000
60000
70000
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060
Shutdown at 40 Y Important investments for new units as soon
as 2017 Lifetime extension (beyond 40 Y) Smoothing the commissionning flow for new build
Current Fleet
Lifetime 40 years
Extension beyond 40 years
Generation 3+
Generation 4
Replacement spread over 30 years (2020-2050)
Construction rate 2000 MW/year
Life extension : a strategic issue
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Life extension : made possible if
Adequate maintenance policy
Structured aging and obsolescence management process and
asset management policy
Efforts to significantly enhance reactor nuclear safety standards
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Aging and obsolescence management
Aging Management Process (AMP)
Compliant with IAEA standards (NS G 2.12 guide)
Approved by ASN (900 MWe series)
Generic AMP procedure : 3 main steps
Identify relevant structures, systems and components (SSCs)
Aging Analysis Sheets (AAS) for selected couples SSC/mechanism
Detailed Aging Analysis Reports (DAAR) for the most sensitive components
Periodic review of AAS and DAAR :
National and International operating feedback
Evolution of maintenance strategies and operating procedure
R&D results on aging mechanisms
Unit DAAR
Obsolescence process
Available and mainly focused on products with short life cycle technologies (I&C,
electrical components).
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Asset management for long term operation
Two different issues
Non-replaceable components (RPV & Containment )
New methodologies and/or modifications
to get complementary margins vs criteria
Replaceable components :
Decision-making process based on
End-Of-Life (EOL) prognosis
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
A non-replaceable mechanical component :
reactor vessel
Prognosis : Expected EOL > 60 years
Good quality (design and manufacturing), good experience feedback.
Two major aging mechanisms
Irradiation embrittlement of the core shells
Thermal aging of the nozzles
Long term operation strategy
No Exceptional maintenance program planned
EOL prognosis based on a deterministic conservative approach
New methodologies required to better evaluate margins
Mechanical and thermo-hydraulic analyses
Probabilistic approach as an in–depth justification
Mitigation and surveillance actions
Low leak core management
Irradiation surveillance program on-site capsules)
Optional : if necessary beyond 40 years , increase of safety injection
temperature
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
A non – replaceable civil work component :
containment (1/2)
1300 MWe and N4 series
Double wall 900 MWe series
Simple wall + liner
Steel liner
Pre-stressed concrete
Pre-stressed concrete
Annulus Venting
System
Reinforced concrete
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
A non – replaceable civil work component :
Containment (2/2)
Simple wall containment ( 900 MWe series )
Current routine maintenance towards 60 years without any major change (periodic air
leak test and in service inspection program).
Corrosion of inner liner : periodic in service inspection
Double wall containment (1300 and 1450 MWe series)
Repair and reinforcing works for preserving inner wall tightness
Improvement of leak treatment system and assessment of resistance to severe accident
conditions based on an experimental program (1/3 scale mock –up) and R&D support
Updating of monitoring system
Reassessment of air leak test conditions (under discussion with ASN)
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Replaceable components
11
SG Replacement
Renovation of
Main Turbine
LP Cylinders
Condenser : Renovation of
1. Tube Bundles of some units
2. Cleaning System
Main Generator
1. Rotor Renovation
2. Stator Replacement
Replacement of Unit
Transformers and
Metal-clad Substations
Replacement of Cooling
Tower Packing
I&C Modernization
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
The french regulatory context
General policy : continuous improvement of nuclear safety
Periodic safety review (PSR) every ten years for each unit, based on up-
to-date nuclear safety requirements
No limited licensing life time but authorisation bg the French Nuclear
Safety Authority, on a case by case analysis for each unit, to operate for
another ten-years period
Numerous modifications already implemented on the plants (after TMI,
Tchernobyl, Blayais site flooding in 1999, summer heat wave in 2003, ...)
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
EDF safety goals for long term operation
Obviating the need to implement countermeasures for the general
public in the event of a design-basis accident
Significantly enhancing plant resistance to hazards
Minimizing time and space-related countermeasures in the event of a
severe accident
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Additional modifications are needed
Reinforcement of interconnections between safety injection system and
containment spray system
Addition of an emergency diesel generator per unit
Modifications to prevent steam generator (SG) overflowing in case of SG tube
rupture
Improvement of containment air tightness, performances of auxiliary buildings
ventilations and efficiency of containment venting and filtration system
Seismic margins reassessment and buildings or equipment reinforcements
...
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
The EDF post-Fukushima action plan (1)
1 Reassesment of the
existing means
Analysis going beyond
the current references 2
The fields which
have been
assessed
Earthquake
Flooding
Loss of heat sink
Station black out
Severe accident
management
If necessary, implementation
of additional means
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
The EDF post-Fukushima action plan (2)
Design bases
Unit compliant with
all criteria of the
safety analysis
report
Hazards beyond
design bases
No cliff edge effect
Highly hypothetic
severe hazards
Hard core of structure
systems and
components to avoid
large releases
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
The EDF post-Fukushima action plan (3)
The current nuclear safety level of each unit of the fleet is acceptable
Nevertheless immediate and mid-term improvements
Emergency planning organization to face accidents involving more than one
unit on a site:
Reinforcement of emergency teams : light equipment and human resources
Set up of a regionally-based “nuclear rapid response force” : operational on-site 24
hours after any accident ; having portable equipment and dedicated human resources
(among them licensed operators)
Renewal of emergency control buildings as regards their protection against external
hazards, their equipment and their autonomy
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
The EDF post-Fukushima action plan (4)
Design modifications (hard core of SSCs)
Installation of one emergency back-up diesel per unit
Reinforcement of spent fuel pool make-up systems
Installation of a last resort make-up water supply (an ultimate heat sink)
Upgrading of the containment filtration and venting system
On a site-based approach, enhancement of protection against flooding and
reinforcement of robustness of some equipment with regards seismic events
...
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Main challenges (1)
Reasonably achievable objectives for improving nuclear safety of existing units
up to 60 years ; methods used
After Fukushima Daiichi accident a new step as been made in the general safety
approach :
the evaluation of robustness of installations far beyond the current nuclear
safety requirements and far beyond their design bases
associated with the definition of a “hard core” of structures, systems and
components (SSC) remaining available and designed to avoid large releases in
case of these extreme accidental situations
This new approach needs to be clarified and codified to address some difficult
questions such as the following :
For what kinds of situation ?
To what extent ? We agree to push reasoning to highly hypothetic situations but
we don't want to go all the way up to total destruction or to totally unrealistic
scenarios
On what bases : purely deterministic, using ALARP codified methods and/or
probabilistic risk assessments ?
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Main challenges (2)
A huge financial challenge : the need for capital expenditures between
2011 and 2025 is 55 Md€2010
Post – Fukushima : 10 Md€ 2010
Other nuclear safety improvements : 15 Md€ 2010
Equipement replacements : 20 Md€ 2010
Operation performances and other patrimonial projects : 10 Md€ 2010
An industrial challenge
Equipment supply chain
Works on site
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime
Main challenges (3)
An organizational challenge for EDF
Engineering, procurement, supplying
Works on-site : how to preserve operational performance (nuclear safety during and after
modifications, units availability, …) as well as people safety
« Grand carénage» = « large refurbishment »
A challenge in terms of human resources
Significant increase of needed manpower
Competencies renewal
Atoms for the future – SFEN - October 2012 - EDF/DIN – J.M. MORONI - Extension to 60 years lifetime